Pyrexia
by Writing Addiction
Summary: When an unrecognized lifeform suddenly shows up on the TARDIS, the Doctor is presented with a choice. He can either risk collapsing several universes in on themselves and getting stuck in a parallel reality to help save a single man's life, or he can live the rest of his life with the knowledge that, somewhere out there in the cosmos, Rose Tyler is grieving. Tough call, right?
1. Presque Vu

_Presque Vu: the sensation of being on the edge of an epiphany._

**Prologue: The TARDIS**

The TARDIS looks through her data files sometimes. Most of the time, it's because she needs to rearrange her archives—past, present, future: why do tenses continue to be so difficult?—but every once in a great while (or perhaps once a week, she can never tell), she goes through them because she feels lonely. No, it's more than that, it's deeper, it's sadder, it's…hmmm. That's strange. She's feeling it now. What does he call it, again?

Nostalgia? Yes, that's it! _Nostalgia_.

She feels nostalgic at times, and so she replays her data and audio files, to remember all of her future inhabitants. No. No, her _past_ inhabitants. She knows them all: Sarah-Jane, Jaime, Tegan, Jo, Liz, Susan, Donna, Amy and Rory, Paige, and all of the others. She remembers every one of them, because they are all precious to the Doctor, to her Thief. He will never forget any of them, not matter how long he may live, because he is a good, loving, and kind man.

…Paige? Which one is Paige? She isn't in any of the files, and yet she remembers her. How very odd.

Not Paige. _Rose_. The blonde one. The beautiful one her Thief loved so much. The one who took her matrix inside herself, who risked her life to help her Thief. She's already said that, hasn't she? Or maybe she will say it in the future? She wishes she could understand the difference sometimes.

She's still confused as to who Paige is, but it's really nothing. Confusion happens when you exist across all points in space and time. She never knows if this is supposed to follow that, or if it goes before, or if Brighton is the name of an Upze girl, or a city-block on an Atrecranos ship, or if it's anything else in any of the known and unknown universes. Confusion is what she does best, and besides, if she is patient long enough, the confusing things are eventually explained.

Maybe if she searches the files linked to the name Paige…? Oh. Right. No files. That is certainly very strange. She archives everything for just this kind of occasion. If it has ever happened or ever will, she archives it. She likes being neat, and it makes things easier for her Thief when he needs a visual link to a memory.

Like right now, her Thief is remembering Rose. The blonde one. The beautiful one her Thief loved so much. The one who took her matrix inside herself, who risked her life to help her Thief. She liked Paige. Paige was nice. Paige was lovely.

Rose. Not Paige. Who is Paige? She doesn't understand. Why are there no files on this Paige person? Anyone who has ever even touched her outer shell has a file. She likes being neat, and it makes things easier for her Thief when he needs a visual link to a memory. But there's nothing on Paige. There's nothing, and yet, she remembers her.

She wishes she could take a corporeal form again and ask her Thief. He would know, surely. Unless it hasn't happened to him yet. Blimey, she always forgets about that part. Her Thief may know, or he may not know, so perhaps there's no point in asking him anyway. His timeline is another thing that confuses her, because it's so terribly linear. He goes from one point to another like he's supposed to, and he never crosses his own time stream, and he never lets her have any fun at all! Though it is quite fun when he lets her sing to him sometimes at night, and when he tells her stories and calls her Sexy when they're alone. She likes being alone with him.

She still doesn't know who Paige is, and this has got to be the single most frustrating thing in the cosmos.


	2. Déjà Vu

_Déjà Vu: the sensation of familiarity with the unfamiliar._

**Chapter 1: River Song**

One of the loveliest things about being pardoned, besides the fact that she's no longer in jail and universally infamous for killing her husband, is that she can go travelling with him and not have to dread going back to a dark cell block when it's over. She has enjoyed her trips with the Doctor more than anything in the world thus far, but the satisfaction of knowing that, when she says goodbye, she won't have to conceal quite so much sadness makes her heart sing. And god knows her new mattress is infinitely more comfortable. She can be a proper archaeologist, too, digging her way through the remnants of civilizations unknown and cultures undiscovered. The Alru mine shafts look particularly interesting, at the moment. She'll have to see if Doctor Pholwise would be interested in coming along. Bioluminescence would certainly come in handy.

She has her notebook rested in her lap, sketching out ideas for what kind of equipment would be needed to explore mines made entirely for the purpose of mining liquids, letting the soft golden glow of the console room give her comfort and just enough light to see what she's writing. The Doctor's off in some corner of the TARDIS or another, probably trying to solve the mystery of the Third Kitchen, also known as The Kitchen That Turns Everything Into Rice Pudding. He'll be back soon enough.

A vague sort of clanging noise comes from below her feet, and it makes her pause for a moment. The TARDIS makes a good many noises, but that isn't usually one of them. Then again, something may well have changed since the last time she was here. She doesn't hear anything else that sounds imminently dangerous, and the old girl doesn't seem frightened, so she lets it go.

After another few minutes, when she's about to look up just how dense the atmosphere would be that far below the surface of Alruni, she hears a different, not-a-normal-TARDIS-noise noise, and it's accompanied by what is definitely shouting. That gets her full attention, because the best-case scenario is that the Doctor's got his jacket stuck in a bit of machinery, and the worst-case scenario is that someone besides herself and her husband is below the deck of the console room. Last time she checked, however, the Doctor's voice wasn't quite that high.

She sets her notebook to the side and walks softly across the floor until she hears the shouting again. When she does, she finds the nearest floor panel and hauls it up, climbing down and doing her best not to step on anything important. She silently apologizes to the old girl when her foot slips and knocks something over, but she manages to land on somewhat solid ground without too much trouble.

She hears it again; it's definitely the sound of someone shouting, and furthermore, it's someone who sounds much more afraid than the last time.

"Hello?" River moves in the direction of the noise, stepping over wires and cords and the occasional piece of machinery she probably shouldn't be touching, bracing herself in case something dangerous popped out. Benign, non-lethal things do not generally appear in the depths of the TARDIS without any explanation.

"Come on!" She can make out words, now, and that's definitely a voice she hasn't heard before. Whoever it is sounds rather terrified. "Somebody, anybody!"

"Yes, yes, I'm here! Are you alright?" She's caught sight of the poor thing: a girl who can't be older than sixteen or seventeen, with short brown hair and two rings through the side of her lower lip. She ducks under a particularly heavy mass of cables, and when she comes back up, she silently checks the girl for a vortex manipulator, or even a funny-looking necklace. She can't see anything on the girl at all that would provide the slightest explanation for her being here.

"Holy shit," the girl rolls her eyes, which has River reaching for her blaster reflexively. "She said it would be hard to find you, but I didn't think it would be like this."

For the first time in a good while, Professor River Song finds herself at a loss for words. "Hard to find…I'm sorry, who are you, exactly?"

Something in the girl's eyes goes a bit sad, and she tucks a strand of hair behind her head. "You don't have a clue, do you? Name's Paige. …you're not the Doctor, are you?"

River lets out a soft breath of laughter in spite of herself. "I'm afraid not." She extends her hand to Paige, who looks a bit confused, but takes it anyway. "Professor River Song. Nice to meet you, Paige. …is there any particular reason you're about twenty feet or so from the engine room of the TARDIS?"

"God, is that why it's so dark in here?" Paige asks, looking around with far less awe and wonderment than anyone first arriving in the TARDIS has any right to. When she turns to her once again, she sighs. "So where is the Doctor, anyway? I really do need to find him rather quickly." The girl glances down at her feet. "It's important."

That is, in fact, a very good question, so River looks for the quickest way back up to the console room. She can't even see the panel she opened to get down in the first place. The old girl decides to be helpful and switch on a few lights along the walkway, and she manages to lead Paige up to a highly convenient ladder.

"Well, he's not down here, or he would have heard us, so let's find him." She does have to knock a box full of what sounds like old books out from on top of the floor panel, but once she's climbed out, she knows where they are and, more importantly, how to get back to the console room.

"Doctor?" She wonders if the TARDIS has some sort of intercom, in case he's gotten lost in the back library, again, but if he _has_ gotten lost in the back library, there's no hope of reaching him for at least an hour.

"Christ," the girl breathes, crossing her arms loosely across her chest. "Mum said he'd do this. Always buggering off to make the most dramatic entrance he can."

"Doctor!" River strides back into the console room, becoming more flustered by the instant. "...I give up. He's sure to turn up if I start flipping switches." She's right about to try and pull up his location on the console's screen when it hits her what the girl just said. "Hold on a moment, 'Mum'? Your mother knew the Doctor? Did she travel with him?"

"It's...it's kind of a long story, probably best told by the man himself, but the short of it is," the girl takes a long breath and sighs, "my mum is Rose Tyler." When she doesn't react in whatever way Paige wants her to, she tilts her head a bit. "If that name even means anything to you at all. It might not, I don't know." She looks around again, as if just noticing they've moved at all. "Where are we now, anyway? Why isn't the Doctor here?"

River doesn't know much about Rose Tyler beyond the fact that she traveled with the Doctor for a long while. Even Madame Kovarian and the Silence hadn't cared to teach her very much about Rose Tyler: "That woman is his biggest weakness. Use that to your advantage, if you can." This whole situation is really starting to climb beyond her field of expertise. She brings up the Doctor's location on the console's screen (third kitchen, she was right), and makes as much noise as possible while doing so in the hopes of getting his attention.

"Husband! We have a visitor," and she hears the faintest of crashing noises from down the hall, which means he should at least be on his way. She turns back to Paige and gives her a somewhat apologetic look. "I think that at least got his attention."

Paige looks around the console room as if she's just now really noticed that they're somewhere different. She circles the console, smiling gently to herself. Well, then. That's odd. The girl is acting as if she's been here before. Before River has a chance to ask her, Paige looks over at her. "When did it change? Mum has a picture of it at home; she and Dad used to tell me stories when I was little about everything they did together before they..." The girl hesitates. After a moment, she shakes her head softly. "It looks different than it did. Why?"

River's raises her eyebrows at little. "Do you know, I remember him telling me about the night everything changed. 'New face, new ship, new rules,' he said." River runs her fingers over the zig-zag plotter affectionately. "The old girl's filled to the brim with regeneration energy just like the Doctor is. I guess she changes, too." _Just like _I_ am_, she thinks, but she has a feeling that bit of information is best saved for another time and place. "What I'd _really_ like to know, Paige," she continues, "is how you managed to turn up in the bottom of the console room, considering we're currently flying through space."

Paige shrugs her shoulders. "I don't really understand it myself. Mum just said it would work if I trusted her, and I suppose it did. There's..." The girl chews on her piercings for a moment, looking intensely sad. "There's a bit of...trouble, back home. Dad is... Mum wants to know if there's anything the Doctor can do for him, you know? So I sort of volunteered to come and find him. Well, I say volunteered. But now I don't even know how to get back home. If we can't find the Doctor, then I'm just stuck here. That's why I need him! Even if he can't help Dad, he's the only hope I have for finding a way back home."

River wonders what sort of trouble this poor girl has gotten involved in, if she came straight to the Doctor for help. What really stands out, though, is the fact that she's here because of her dad. Not her planet, not her species, not even her city. Her dad. River can't decide if that's more or less foreboding than the distress calls the Doctor normally gets.

"The Doctor is here, even if he's taking his time, and I can promise you, he will get you back home." She doesn't make promises much, these days, but she feels fairly confident in that one. After all, she knows the Doctor well enough to know he can't stand seeing people like Paige, lost and afraid.

The girl shakes her head and crosses her arms again. "No, you don't understand. He's dying. Dad's dying, and there's nothing anyone else can do for him. We've taken him to loads and loads of doctors back on Earth, and they've done loads and loads of tests on him, and they all say that he's fine, that they don't know why he's feeling bad." She takes a breath and her throat hangs on her for a moment. When she regains her composure, River notices the tears welling up in her eyes. "He's pale and gaunt and he can barely move sometimes, and every breath seems like it's going to be his last, but his eyes have years and years of life left in them. It's like...it's like his body has given up on him and his brain is the only thing that's left. Mum's about to go mental over it." She covers her eyes with her hands in vain attempt to hide her tears. "I have to find the Doctor."

River wonders if Paige is confused, somehow, because even though he calls himself the Doctor, River's pretty sure he isn't actually a certified medical professional. He specializes more in apocalyptic scenarios. Still, if her mother was the Doctor's companion, she ought to know that. "Paige...if you don't mind my asking, who is your father, exactly?"

She nearly regrets asking, because the girl looks up at her like she's gone mad. After a moment, her expression softens slightly. "Don't suppose he talks about it much, then. But it's...kind of complicated." She sighs again, and judging by the expression on her face, the poor thing has no idea where to begin. "Do you know what a metacrisis is?"

Her heart sinks in her chest, and suddenly the room feels far too cold. She knows what a metacrisis is, yes, but it's one of many things she wishes she had never learned. If there's another Doctor out there, slowly dying with no way to explain why, then she might have to extract the man from that infernal kitchen and bring him here, herself. "Your father is the metacrisis Doctor."

Paige frowns. "Yeah. Only got one heart and everything. Mum says that's why the Doctor's the only one who can save him."

If Paige's father is the Doctor, she reasons, then it _would_ follow that only the Doctor could help. Damn that man. She's not entirely sure what to do now. This girl is on the verge of breaking down, and for once in his life, the Doctor is not making dramatic entrances. She lays her hand on the girl's shoulder, trying to give her some small amount of comfort if she can, and after a few moments, she distantly hears someone running down the great hall. The Doctor eventually comes barrelling into the console room, his arms and hair flying wildly.

"River! River Song! Get out of the console room, I've got to lock it down, the TARDIS just detected another lifeform's sudden appearance in here, and until I found out who it is and why and how they've bloody invaded my poor TARDIS—" He stops short when he notices that the "intruder" is nothing more than a scared human girl. "Oh. Well then." He adjusts his jacket and bowtie and calmly walks over to them. "Hullo. I'm the Doctor." He smiles at her quickly before his confused expression returns. "If I may ask...how did you get into my TARDIS mid-flight, miss? There's not many people who can do that..."

River smiles to herself. Dear god, he's interested already. He's like a six-year-old with a new toy. He's going to turn her over and see how she works, and all the while, she'll not have any idea what's going on. Should be interesting.

"Hello, sweetie. This is Paige Tyler. She's here because her dad needs your help." She pauses for a moment. "No, your name wouldn't be Tyler, would it? Not if you live on Earth. I'm assuming you do. Some time in the early 21st century, going by your clothes and jewelry?" Now isn't really the time for it, but anthropology was always one of her favorite classes. It certainly made things more interesting when she went and visited at least half of the civilizations she had studied in school.

"Oh." His face falls a bit. "..._Tyler_? No." He takes a step closer to her and just stares, like she's a race of aliens he's never met before now. Yet, there's a great sadness in his face, and River knows she doesn't know enough about Rose Tyler to understand it. "No, no, no. But you can't-you can't be here. There's no way she could have... And even if she could have, she just..." He pauses, squinting his eyes at her. "You dad? What's going on with your dad, then?"

Paige shoots them both a look. "No, it's isn't Tyler, it's Smith. Paige Smith." She stares back at the Doctor for a moment, and suddenly, she gives him a shove. "Stop staring. It's rude to stare, you know." The Doctor laughs, and Paige just rolls her eyes. River can't help but smile at them. This little partnership is either going to go very well, or very, incredibly badly. Paige straightens her shirt and continues. "Anyway, Mum sent me to find you. Dad's sick, the human doctors can't do anything for him, and Mum wants you to see come and see if you can help him."

"From what Paige was telling me, it sounds a bit like..." River wonders how to put this delicately enough not to send Paige into a panic attack. "Well, I think it might be something the human doctors wouldn't be able to detect even if they knew what to look for. It would certainly be helpful if we could see him in person." She watches the Doctor take in everything, and even though he's wearing his poker face right now, she can tell he knows what she means. Keeping one eye on him and the other on Paige is going to be a difficult but worthwhile endeavor. "Paige, where does your family live?"

She looks up at the Doctor. "We used to live in London, but Dad got a job offer in Brighton a couple years ago. It's right near the beach, our house. It's really nice." Paige gets a far-away look in her eyes, and River can see how frightened and how lonely she feels. The sooner they can get this poor thing home, the better. For everyone involved.

The Doctor grins, laughing softly. "Brighton? Near the beach? Blimey, I never thought Rose would ever leave London. She's a Londoner through and through, is my Rose Tyler." The Doctor claps his hands together, slow to realize his mirth and his use of the possessive is completely unwarranted in the situation. When he does, he clears his throat and runs a hand over his chin. "Yes, right then. Brighton."

The Doctor spins around, looking up at the scanner and hitting a few buttons on the console. River can see how he's trying to assimilate everything in his mind, and she can't imagine the sort of emotions are going through his head.

Paige starts to nods off soon, and after they finally manage to find the spare bedroom, the rest of their evening is spent trying to figure out how to get this sweet, scared girl back home to her parents.

"How are we going to do this, Doctor?" she asks quietly.

"I don't know, River, I just..." He sighs dejectedly, scrubbing his fingers through his hair. "I don't know, and I hate not knowing."

She takes his face in her hands, kissing his mouth lightly. "Let's call it a night, husband. We'll be better equipped to deal with this after we've had some sleep."

He doesn't look like he's on the same page as her, but with a tortured sort of look in his eyes, he gives in. As they make their way back to their room, she wonders at the sort of implicit trust and undying faith Rose Tyler must have in the Doctor to send her daughter across the dimensions in search of him.


End file.
